The present invention relates generally to document handling systems, and more specifically to a novel method and apparatus for efficiently depositing a stack of documents onto a feed ramp which conveys the documents toward sequential processing stations.
It is common practice in the automated handling of documents, such as mailing envelopes and flats, to progressively feed a stack of documents in a feeder station, feed ramp or magazine to a shingling station and then to a singulating station. The documents are then directed from the singulating station as separated single documents to sorting stations or other processing stations and devices.
Postal requirements demand that a high volume of documents be handled in a short period of time. Typically, document handling devices are required to process thousands of documents per hour with a minimum of sorting defects and product damage. If documents cannot be fed rapidly enough to the processing stations, system throughput is reduced.
Typically, the first stage in the document handling process after the documents have been placed in a container or tray with the address labels or indicia facing the same direction, is to load the stack of documents onto some form of feed transport mechanism, such as a conveyor belt mechanism. The tray is then generally grasped by an operator, lifted, and essentially "dumped" onto a feed ramp or conveyor belt device. The conveyor mechanism then directs the documents toward the various separators, shinglers and sorting devices.
Known systems and methods typically require substantial human intervention and action to load the stacks of documents from the tray onto the document transport mechanism. The operator must gather the stack of documents or lift the tray and place the documents on the conveyor belt so that all of the documents are in an on-edge orientation. The trays containing the documents are heavy and cumbersome and typically require up to forty-five to sixty seconds or longer to unload. Such manual unloading often causes the edges of the documents to become unaligned which further reduces system throughput as the documents are routed to the various processing stations.
Often, multiple operators are employed to unload multiple trays in an attempt to increase system throughput. Hiring multiple operators to perform the same repetitive operation is expensive and inefficient. Additionally, the above-described unloading process must be performed while taking steps to prevent a previously unloaded stack of documents from falling over. Unloading is typically performed as the conveyor belt is continuously advancing the stack of documents toward the various processing stations. This is a time-intensive process and is one of the limiting factors in achieving high-speed document processing and throughput. Such inefficient steps increase document processing costs and may even cause operator injury, such as repetitive stress injuries.
The documents are typically transported to an initial processing station, such as a shingling station, prior to singulation. Shingling results in orienting either the top or bottom document in a vertical stack, or the front or lead document in a stack, so that the forward or leading edge of each successive top, bottom or front document is disposed slightly forwardly or laterally of the leading edge of the next adjacent document, preferably by a distance of approximately one inch. By shingling the stacked documents, only one document at a time will enter a nip defined by singulating belts or rollers, thereby substantially reducing the possibility that more than one document at a time will be fed simultaneously through the singulating belts or rollers. The singulating belts or rollers then transport each document in an on-edge single file manner towards other sorting and processing devices. The present invention can also be used to feed documents sequentially into a singulation apparatus, where shingling of the documents is not required.
Thus, a method and apparatus which significantly increases the efficiency of loading stacks of documents onto a conveyor system would greatly improve the rate at which documents could be handled in a document processing system.
Accordingly, it is a object of the present invention to substantially overcome the above-described problems.
It is another object of the present invention to provide a novel tray unloading apparatus which allows rapid and efficient unloading of documents from a tray or bin onto a conveyor system.
It is a further object of the present invention to provide a novel tray unloading apparatus able to provide document processing stations with documents at a rate of over ten thousand documents per hour.
It is also an object of the present invention to provide a novel tray unloading apparatus configured to urge the edges of the documents against reference surfaces.
It is still an object of the present invention to provide a novel tray unloading apparatus that promotes ergonomically correct manipulation and unloading of trays of documents.
It is yet another object of the present invention to provide a novel tray unloading apparatus that automatically urges the documents towards a parallel orientation relative to a bottom and a side wall of a feed ramp device.
It is also an object of the present invention to provide a novel tray unloading apparatus that allows a tray to be unloaded by a single operator in less than thirteen seconds.
It is yet a further object of the present invention to provide a novel tray unloading apparatus that allows a reduction in the number of workers required to unload documents from the trays.
It is still a further object of the present invention to provide a novel tray unloading apparatus having pneumatic actuators to control movement of the apparatus under computer control.
It is another object of the present invention to provide a novel tray unloading apparatus that automatically pivots and rotates a container or tray of documents under computer control.
It is a further object of the present invention to provide a novel tray unloading apparatus having a tray removing portion that automatically engages the tray and removes the tray from the unloading apparatus after the documents are in position to be unloaded from the tray.